BaiduAPI::getRefreshToken PHP Method

    public function getRefreshToken()
    {
        $session = $this->getSession();
        if (isset($session['refresh_token'])) {
            return $session['refresh_token'];
        } else {
            return false;
        }
    }

 function checkUser()
 {
     $baidu = new BaiduAPI(BAIDU_KEY, BAIDU_SECRET);
     $access_token = $baidu->getAccessToken();
     $refresh_token = $baidu->getRefreshToken();
     $user = $baidu->getLoggedInUser();
     if ($user) {
         $_SESSION['baidu']['access_token']['oauth_token'] = $access_token;
         $_SESSION['baidu']['access_token']['oauth_token_secret'] = $refresh_token;
         $_SESSION['baidu']['isSync'] = 0;
         $_SESSION['baidu']['uid'] = $user['uid'];
         $_SESSION['open_platform_type'] = 'baidu';
         return $user;
     } else {
         return false;
     }
 }